Temperature Optimization Within 2 Uniquely Designed Courier Lockboxes During Extreme Summer Temperatures
Stephanie Hart1, Joesph R Wiencek2
1Vanderbilt University School of Medicine, Nashville, TN, USA.
Objectives:
To determine optimal temperature profiles for 2 uniquely designed courier lockboxes (steel vs polymer) by standardizing daily ice (-20ºC) and cold (4-8ºC) pack placement.
Methods:
Paired courier lockboxes were placed outside in direct sunlight. Ambient outdoor and lockbox temperatures were monitored during 2 4-day cycles, and temperature mean and range were determined daily (time frame, 4:00-10:00 pm). Control lockboxes without packs were compared with experimental paired lockboxes with either 2 cold packs placed at 4:00 pm or 4 ice packs placed at 8:00 am and replaced with 4 cold packs at 4:00 pm daily.
Results:
Cycle 1 mean temperatures within control steel and polymer lockboxes were 31.8ºC (range, 18.4-44.1ºC) and 37.2ºC (range, 27.1-46.7ºC), respectively. The addition of 2 cold packs at 4:00 pm reduced mean temperatures to 29.1ºC (range, 19.1-37.2ºC) and 25.3ºC (range, 20.0-31.6ºC) in steel and polymer boxes, respectively. Cycle 2 mean temperatures within control steel and polymer lockboxes were 28.3ºC (range, 22.4-40.8ºC) and 31.6ºC (range, 23.8-41.0ºC), respectively. The addition of 4 ice packs at 8:00 am and replacement with 4 cold packs at 4:00 pm reduced mean temperatures to 24.3ºC (range, 17.4-27.9ºC) and 13.4ºC (range, 6.6-18.1ºC) in steel and polymer boxes, respectively.
Conclusions:
Standardizing instructions for ice and cold packs can decrease internal courier lockbox temperatures.
Related Concept Videos
Hot Weather Concreting
Mitigating the heat increase in concrete can be economically achieved by shading aggregate stockpiles to prevent heating from solar radiation,...
Masonry in Cold and Hot Weather Conditions
Other key practices include keeping masonry units...
Mass Concreting
To reduce the risk of such cracking, the concrete mix may incorporate low-heat cement and pozzolans to reduce the temperature rise. Pre-cooled angular aggregates and water-reducing admixtures...
Cold Weather Concreting
To counteract the negative impacts of cold weather, ensuring...
Thermal expansion and Thermal stress: Problem Solving
To solve the problem, first, identify the known and unknown quantities. The initial length (L) of the bridge is 1275 m, the coefficient of linear expansion (α) for steel is 12 x 10-6/°C, and the change in...
Diversity of Archaea IV


